【发布时间】：2015-07-15 22:29:10
【问题描述】：
我想在 C 中创建一个循环，当程序要求一个整数并且用户键入一个非数字字符时，程序再次要求一个整数。
我刚刚找到以下代码。但我不明白这是什么意思scanf("%*[^\n]%*c")。 ^\n 是什么意思？ ^\n和c前面的*是什么意思？
/*
This program calculate the mean score of an user 4 individual scores,
and outputs the mean and a final grade
Input: score1, score2,score2, score3
Output: Mean, FinalGrade
*/
#include <stdio.h>
//#include <stdlib.h>
int main(void){
int userScore = 0; //Stores the scores that the user inputs
float meanValue = 0.0f; //Stores the user mean of all the notes
char testChar = 'f'; //Used to avoid that the code crashes
char grade = 'E'; //Stores the final
int i = 0; //Auxiliar used in the for statement
printf("\nWelcome to the program \n Tell me if Im clever enough! \n Designed for humans \n\n\n");
printf("Enter your 4 notes between 0 and 100 to calculate your course grade\n\n");
// Asks the 4 notes.
for ( ; i<=3 ; i++ ){
printf("Please, enter your score number %d: ", i+1);
//If the note is not valid, ask for it again
//This is tests if the user input is a valid integer.
if ( ( scanf("%d%c", &userScore, &testChar)!=2 || testChar!='\n')){
i-=1;
scanf("%*[^\n]%*c");
}else{ //Enter here if the user input is an integer
if ( userScore>=0 && userScore<=100 ){
//Add the value to the mean
meanValue += userScore;
}else{ //Enter here if the user input a non valid integer
i-=1;
//scanf("%*[^\n]%*c");
}
}
}
//Calculates the mean value of the 4 scores
meanValue = meanValue/4;
// Select your final grade according to the final mean
if (meanValue>= 90 && meanValue <=100){
grade = 'A';
} else if(meanValue>= 80 && meanValue <90){
grade = 'B';
} else if (meanValue>= 70 && meanValue <80){
grade = 'C';
} else if(meanValue>= 60 && meanValue <70){
grade = 'D';
}
printf("Your final score is: %2.2f --> %c \n\n" , meanValue, grade);
return 0;
}
【问题讨论】：
标签： c user-input scanf format-specifiers